So, after using the iPad Pro for a number of weeks now, I figured I'd update my experience with it and offer my insight (for what it's worth) and ask for some help.
Several weeks ago, as I was about to lecture, the Pencil warning popped up saying it had less than 5% charge. I had forgotten to recharge it lately. Because I had to lecture right away, I figured I would just plug in the Pencil via an extra lightening cable to a USB charger and let it charge while I used it write notes.
Issue 1: I'm not sure why Apple insisted on the inverted Lightning connector, as well as the Lightning coupler, for the Pencil. From my perspective, the coupler is just another, very small gadget that can be lost, and yet sort of needs to be carried everywhere for those just-in-case instances.
Issue 2: After I plugged in the Pencil to charge, I could not get it to work with the iPad! The Pencil would not register on the screen while it charged. Does anybody else have this issue? Is it just me? I ended up using the whiteboard - how archaic.
I had tried GoodNotes for some note taking during meetings, and it worked well. So, I used it to lecture the next week (after remembering to charge the Pencil!). Except, when I tried to pinch zoom in on the iPad to enlarge the projected image on the screen for students in the back to better see, nothing happened. The zoom ratio seemed fixed. So, I went back to Notability where I could zoom in on the screen and it would also do so on the projected image on the screen.
I'm generally happy with Notability but I wanted to try GoodNotes because of its slightly better organizational structure, graphics engine (for making straight lines and circles), and because I could tell where page breaks were. I found that Notability would cut me off at various page breaks. However, I see now that you can see the page breaks on Notability - they're just really, really faint.
Can I zoom in GoodNotes while projecting to an external screen?
Some days, I think a Surface Pro would have served my needs better because, frankly, it is a regular computer and so I have more multi-tasking options. The iPP is still a tablet afterall. On the other hand, I haven't used the table overly much - as I suspected - so that would have meant having a much more expensive Surface just sitting around. And I still can't stand Windows updates.
At the end, I think the ideal combination is to have both a computer and an iPad - with the iPP literally being an electronic notepad.